Hand-position indicator for typewriters



Sept. 23, 1947.

s. SIEURIN HAND POSITION INDICATOR FOR TYPEWRITERS Filed Oct. 3, 1945 IN VEN TOR MW'W/J B2 @ZLT Patented Sept. 23,1947

HAND-POSITION INDICATOR FOR TYPEWRITERS Sven Sieurin, Stockholm, Sweden,assignor to Aktiebolaget Atvidabergs Industrier, Atvidaberg, Sweden, acorporation of Sweden Application October 3, 1945, Serial No. 620,023 InSweden October 10, 1944 7 Claims.

When persons are instructed and trained in ypewriting they incessantlymust be told not to lower their hands and wrists but to hold them sohigh that the fingers are directed down against the keys.

The present invention has for its object to provide in typewriters adevice for indicating the position of the hands when lowered, so that itis automatically pointed out to the typewriting person and to theteacher when the wrist of a hand is held too low and, thus, the positionof the hand immediately can be corrected.

Another object of the invention is to provide a highly sensitiveconstruction of a control device of said type, so that this device isactuated even by a light touch of the hand.

Still further objects will appear from the following description of apreferred embodiment, by way of example illustrated in the annexeddrawing, in which:

Fig. 1 shows diagrammatically a plan of a typewriter provided with adevice according to the invention;

Fig. 2 shows a longitudinal section through a left hand portion of thecontrol device;

Fig. 3 shows a longitudinal section through a right hand portion of thecontrol device.

The typewriter may be of any kind. In Fig. 1 only the outlines of somemain details are indicated, viz. the platen at I the rockable cover at2, the frame at 3 and the keyboard at 4.

The device for indicating the position of the hands when lowered,comprises, according to the invention, an electric indicating element, acircuit for supplying electric energy to said indicating element, and acircuit controlling member mounted yieldingly in front of the keyboardof the machine-to close said circuit when depressed by the wrist of alowering hand.

This control member may be formed as an U- shaped fork, the middleportion of which extends horizontally in front of the machine, the twolateral end portions of this fork being mounted on the frame of themachine, preferably in an adjustable way so that the position of saidmiddle portion in relation to the keyboard can be adjusted in verticalor horizontal direction or in both these directions.

The middle portion of said U-shaped control fork consists of twoconcentric cylindrical spiral springs 6 and 7, made of an electricallyconducting material, such as steel, bronze or the like, and constitutingelectric contacts. The two end portions of said fork, which end portionsserve as holding members for said springs, consist of tubes 8 which alsoare made of steel, bronze or the like and the ends of which are benttowards each other. Around these ends of the two tubes the outer spring6 is securely mounted and in the interior of each one of the same tubeends an insulating body 9 is mounted (see Figs. 2 and 3). Theseinsulating bodies have extensions in the shape of concentric studs 9upon which the inner spring 7 is attached. Thus, the two springs areinsulated from each other when they are in stretched condition.

The lateral tubes 8 of the control fork are mounted on the frame of themachine by means of fastening members If]. These members may consist ofU-shaped or angular brackets which are mounted beneath the side portionsof the frame of the machine in such way that the vertical portions ofsaid U-shaped brackets are in contact with the lateral surfaces of theframe. Each bracket may be fixed to the machine frame by means of ascrew I l which has a knurled head I l and also carries two jam discsl2, l3 for the lateral tube 8. These jam discs may have diametricalgrooves for the tubes 8. The contact surface between the bracket l0 andthe inner jam disc i2, may be milled.

The innner spring I is electrically connected with one end of a wirestrand I6 which is passed through a channel in the insulating body 9 ofone of the tubes 8 and further through this tube to an electricindicator or signal element in the form of a lamp I8 which, preferably,is mounted on the front side of the machine above the keyboard, forinstance, inside a window in the rockable cover 2 usually arranged overthe type-levers. From this lamp the circuit runs to one of the poles orterminals of a battery 20, for instance, located in the machine. Thisbattery may be a cell of the type normally used for electric torches.The other terminal of said battery is connected with the machine framewhich, thus, together with one of the tubes 8 constitutes one of the twobranches forming the electric circuit.

Evidently, the outer spring 6 will yield for even the lightest touch andwill then electrically engage the inner spring 'I, so that the circuitover the lamp I8 is closed. When the lamp is lighted the attention ofthe writing person is called to the fact that he holds the hands in anon-correct position and, thus, he immediately can correct the positionof the hands. Also the teacher will observe the signal from the lamp. Ofcourse, also an acoustic signal device may be used instead of the lamp,for instance electric bells, buzzers or the like, or other electricallyactuated signal or indicator devices.

The device according to the invention can easily be mounted on machinesalready in use, the holding device being made in correspondence to thetype of machine in question. However, the device according to theinvention can be incorporated in the machine even by the manufacturer ofthe same.

What I claim is:

1. In typewriters, a device for giving an alarm when the hands andwrists are lowered, comprising, in combination, an electric alarmelement, a circuit for supplying electric energy to said alarm element,and a circuit control member mounted yieldingly in front of thekey-board of the machine to close said circuit when depressed by theWrist of a lowering hand, said control member extending laterally alongthe whole front side of the key-board.

2. In typewriters, a device for giving an alarm when the typist lowersher wrists, comprising, in combination, an electric alarm element, acircuit for supplying electric energy to said alarm element, twoelectric contacts in said circuit, said contacts being suificiently longto extend laterally along the whole front side of the key-board, andmeans for mounting said contacts in front of the key-board of themachine parallel to each other and one above the other, at least theupper of said contacts consisting of a spring deformable to engage thelower contact when depressed by the wrist of the typists hand.

3. In typewriters, a device for indicating the position of the handswhen lowered, comprising, in combination, an electric indicatingelement, a circuit for supplying electric energy to said indicatingelement, two lateral holders attached on the frame of the machine andextending to points in front of the keyboard of the same, two electriccontacts in said circuit, which contacts consists of two cylindricalspiral springs concentrically extending between said holders, andinsulating means in said holders to insulate said springs electricallyfrom each other, the outer one of said springs making contact with theinner one when depressed by the wrist of a lowering hand.

4. In typewriters, a device for indicating the position of the handswhen lowered, as claimed in claim 3, comprising, in combination, alsothe feature that said holders are adjustably mounted in the frame of themachine to allow adjustment of the position of the springs in relationto the key-board of the machine.

5. In typewriters, a device for indicating the position of the handswhen lowered, as claimed in claim 3, comprising, in combination, alsothe features that said holders consist of metal tubes the end portionsof which are bent towards each other and carry externally the outerspring, and that said insulating means consist of insulating bodiesarranged in said tubes and carrying the inner spring.

6. In typewriters, a device for indicating the position of the handswhen lowered, as claimed in claim 3, comprising, in combination, alsothe features that the outer spring is connected to one terminal of anelectric source over the holders and the frame of the machine, and thatthe inner spring is connected to the other terminal of said source overa wire strand located in one of said holders, the electric indicatingelement being connected between said electric source and said wirestrand.

7. In typewriters, a device for indicating the position of the handswhen lowered, as claimed in claim 3, comprising, in combination, alsothe feature that said electric indicating element consists of a lampmounted on the front side of the machine above the key-board.

SVEN SIEURIN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number

